1. Field of the Invention
The present invention relates to image capturing systems.
2. Description of the Related Art
When an object is photographed using an image capturing unit such as a camera, there are many cases where the object is photographed using not only natural light but also light emitted from a light source such as a fluorescent lamp or LEDs. However, when the object is photographed using light emitted from the light source, there are cases where the emission light is specularly reflected on the surface of a document depending on materials thereof, which degrades the quality of an image. Thus, there are conventional image reading devices in which a light source is arranged at a position facing a direction in which specularly-reflected light reflected on the document is not incident to the image capturing unit (for example, Japanese Laid-open Patent Publication No. 7-7605 and Japanese Patent No. 3759887). In addition, there is another technique for suppressing the degradation of the quality of the image due to specular reflection on the document in which two light sources are arranged and emit light in a time divisional manner, the object is photographed using the image capturing unit at the time of emitting light from each light source, and the two images are synthesized together (for example, Japanese Laid-open Patent Publication No. 2001-268323).
However, when the document that is the object is curved, a position at which specular reflection is made on the document may be different from a position at which specular reflection is made on a flat document. Accordingly, when the position of the light source is arranged at the position at which specularly reflected light reflected on the flat document travels toward a direction other than the direction for the image capturing unit, in a case where a document to be photographed is curved, there is concern that specularly reflected light reflected on the document travels toward the image capturing unit and is incident to the image capturing unit.
In addition, since specular reflection differs depending on materials of a document, there are cases where emission light emitted from the light source is not specularly reflected on the document. In such a case, even when two light sources are arranged, there are cases where it is not necessary to cause the two light sources to emit light in the time divisional manner and to synthesize two images. Accordingly, it is very difficult to appropriately decrease the degradation of the image quality due to specularly reflected light reflected from the document regardless of the form of the document.